DE2418300A1 - DRUM FOR RECEIVING A BELT BELT - Google Patents

Description

4690 Herne, 8000 Munich 40,

Freiligrathstrasse 19 r »■ ι ι η 11 η ι. Eisenacher Strasse 17

^p ° stfach 140 Dipl.-Ing. RH Bahr PA-Anw. Betzier

Dipl.-Phys. Eduard Betzier * - «■■ J Dipl.-Ing. W. Herrmann-Trentepohl

Telegram address: «-» * i-

Bahrpatente Herne PATENTANWÄLTE ÄatMün ^ en

Telex 08229853? Δ 1 R 3 Π Ω TeIex521S360

Γ " ~ I bank accounts:

Bayerische Vereinsbank Munich 952 Dresdner Bank AQ Herne 7-520 489 ■ · '. Postal check account Dortmund 558 68-467

** '■ MO 4678 Sk / kr

please indicate in the answer

Please send a letter to:

Applicant;

American Safety Equipment Corporation

Drum for holding a belt

Priority: 2o. April 1973, USA, Serial No. 353, 211

The invention relates to a drum for receiving a belt or the like and relates to an inertial drum or on a drum actuated by inertia forces,

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in which a belt strap or safety belt is added.

The use of inertial drums for restraint and position adjustment of a person sitting on a seat of an aircraft, motor vehicle or the like Inmate is already

known. Such drums allow unwinding the strap or safety belt to allow the occupant to lean forward or other, engage in limited activities. When the vehicle suddenly brakes or moves forward suddenly of the occupant, these drums prevent further unwinding from the drum to restrain the occupant and avoid injury.

In some inertial drums, spools form part of the device on which the superfluous tape or Webbing is stored due to a spring tension. The blocking system of these facilities is normally designed so that each lengthening or pulling out of the belt tension forces at the moment subject to an impact of the vehicle or the like, this resulting in sudden deceleration of the vehicle results. In order to restrain the vehicle occupant, a further unwinding of the belt is carried out prevented by blocking the coil against the frame or frame of the device.

This blocking is achieved by engaging a pawl in a ratchet wheel, which rotates with the Coil is connected. The pawl can be forced into engagement by any means, either

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a resulting deceleration of the vehicle in the event of an accident or the movement of the belt from the spool detects when the occupant is thrown forward. Both times the spool turns at the time at which the pawl is to come into engagement with the ratchet wheel.

In these cases, the first contact between the pawl and the tooth of the ratchet wheel is between the Tips of the pawl and the tooth are made. At the point in time at which this contact occurs, shortly after impacts the vehicle, the coil accelerates sharply and the kinetic energy of the occupant gets in A considerable potential emerges to pass heavy loads on the belt and the ratchet wheel to the To put on the latch. When the radial contact or radial engagement between the pawl and the ratchet wheel is small, the pawl tip may shear or shift and move the pawl out of engagement. The sudden release of belt tension when this occurs and the continued forward movement of the occupant opposite the vehicle allows the reel speed to increase further and the time segments , in which the teeth pass the pawl tip, are used for subsequent engagement too short. In such a case the result is catastrophic as the restraint mechanism fails completely.

In U.S. Patents 2,923 ^ 92 and 3,386,683 it was suggested that use multiple snap-in pawls to engage a toothed wheel, which is attached to a shaft of a winding drum in rotary motion with the shaft. The order

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a plurality of pawls is here essentially the same and the pawls are arranged in such a way that that they work with the teeth of a gear or Ratchet wheel into engagement. The top of the pawl is in engagement with a tooth of the Ratchet wheel. At the same time, the lowest pawl is in a position to engage into a subsequent tooth of the wheel. However, if the top latch is in the outer tip of the associated Gear engages, the lowermost pawl could be too close to the associated gear to timely to intervene in this if the top pawl is not in engagement with the respective gear got. This arrangement thus fails if the tip of the tooth of the ratchet wheel breaks off afterwards it is touched by the associated pawl tip.

The invention is primarily based on the task to provide a locking device for an inertial drum or the like that effectively has a accelerating role in the frame of such drums blocked or stopped to unwind to prevent further seat belt from this.

This object is achieved according to the invention in that a frame with a rotary movement therein mounted shaft, with one end of the webbing connected to the shaft for winding on the shaft is a spring means connected to the shaft and the frame for rotating the shaft in one direction for the purpose of retracting the webbing around the shaft, one rotatable with the shaft and on whose scope attached ratchet gear with a

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2A18300

Plenty of spaced apart teeth that are in a direction of rotation of the Opposite shaft due to the spring device Direction extend and a facility for locking a rotation of the shaft in a direction of rotation of the shaft due to the spring device opposite direction is provided that the locking device two attached to the frame Has locking rods, each having a pawl tip and within the frame from a first, out of engagement with the ratchet wheel to a second, in engagement are movable with the ratchet wheel position that the pawl tips in the second position have such a distance from each other that with a radial alignment of the pawl tip of the one Locking rod to one tooth of the ratchet wheel the other pawl tip of the second locking rod on the ■ Center between two adjacent teeth of the ratchet wheel. Is aligned.

The invention thus advantageously creates a drum acted upon by inertial forces, in which a sita belt is wound around a rotatable shaft. The drum has a spring device for retracting the belt and one attached to the shaft for rotation with it Toothed ratchet wheel on. If the belt is quickly unwound from the shaft, one speaks to inertia forces appealing device or an inertia-sensitive device and actuates two Locking rods for engagement in a ratchet wheel and

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to stop this clinic wheel. Each locking bar contains a pawl tip and when one of the pawl tips is radially aligned with a tooth tip of the ratchet wheel, the other pawl tip is in alignment with the center between two adjacent teeth. When the locking bars are moved into engagement with the ratchet wheel, the two ratchet tips and their alignment with respect to the teeth of the ratchet wheel _t ensure that at least one tip is in a favorable position to engage the ratchet wheel in the event the other tip is used bend away. should or should not come into contact with the ratchet wheel.

Advantageously, two pawls are provided so that if one pawl does not fit into the teeth of the ratchet wheel engages, the other pawl is so convenient that it engages the ratchet wheel. In addition, a differential device can advantageously be used so that in the event of a ricochet a pawl or, if the pawl comes out of engagement with the ratchet wheel, the differential device automatically creates an additional drive to engage the other pawl.

In the following, preferred embodiments of the invention are explained in more detail with reference to drawings. It lines:

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Figure 1 is a vertical, partially in section View of a drum actuated by inertia forces,

FIG. 2 shows a side view of the drum according to FIG. 1, the belt strap being completely pulled out,

FIG. 3 shows a cross-sectional view of part of the -Troiamel device according to FIGS. 1 and 2,

FIG. 4 is a view similar to FIG. 3 for illustrative purposes an engagement of the locking rods according to FIG. 3 in the ratchet wheel of the drum according to FIGS. 1 and 2,

Figure 5 is a cross-sectional view of a modified one Locking device for the ratchet wheel of the drum according to FIGS. 1 to 4,

FIG. 6 shows a cross-sectional view of a further, modified locking device for the ratchet wheel of Drum according to FIGS. 1 to 4,

FIG. 7 is a partial view of a further modification of the locking device for the ratchet wheel of the drum according to FIGS. 1 to 4, and

FIG. 8 shows a section along the line VIII - VIII in FIG. 7.

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In Fig. 1, an inertial drum 10 is according to the Invention shown, which a frame 11 and one attached to a main shaft 13 (Fig. 2) and Has toothed disk 13 arranged coaxially. The webbing l4 is wound around the shaft 13 or around the skins 13 so that the webbing is selectively withdrawn from the drum 10 or wound into the drum 10, as is generally the case is known.

The shaft 13 is arranged for rotation within the frame 11 by at each end of the shaft 13 Storage devices 15, 16 stored and fastened within the frame 11 such that they can rotate.

As can be seen from Fig. 2, the tape lk is in its fully extended position and is guided by a guide 17 with rollers 18 located therein to reduce friction on the tape ik when it is pulled through the guide 17; the band or belt strap lk can consist of nylon or a synthetic fiber or some other suitable marial. A lid 19 can be rotatably connected to the guide 17 so that the drum 10 can be enclosed by the lid 19 when the tape lk is retracted therein. The free end of the band l4 ends in a connecting element 20 for connecting the band l4 with a complementary "not shown in the drawing closure element, which in turn can be attached to a vehicle or can form part of a similar band arrangement.

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In Fig. 1 is on one side of the frame Π a conventional spring socket connection shown. The connection or unit 21 should be a suitable torsion spring 22 or the like, which mutually influence the shaft 13 and the frame 11 lets to feed the tape l4 normally or to withdraw. A suitable arrangement that can be used here is in U.S. Patent 3,074,761 described.

A guide flange 23 is arranged between the inside of the frame 11 and the belt 14t, so that a guide is created between the flange 23 and the toothed washer when it is pulled out of the frame 11. A support element 2h extends over the drum 10 between the sides forming the frame 11, as shown in the drawings. The flange 23 may also include a gear suitably spaced thereon.

According to the invention, devices for locking the toothed disk 12 are provided in particular. In a preferred embodiment, the locking device has two elongated rods 25 »26, which are arranged on the frame 11 according to FIG. As can be seen from FIG. 2, the side wall 27 of the frame 11 contains two openings 28, 29. It can be seen from FIGS a and 51a, which extend out of the openings 28, 29 - the openings in the opposite side wall 30 of the frame 11 cannot be seen in FIG. The new noticeably be N _ac h _S tehend

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paint of the Sperrstaii ^ en 25 _t 26 explained in more detail.

Between the sidewalls 27 and 30 extends over the bottom of the frame 11 a support bsvr. Retaining element 31. As can be seen from Fig. 2, a back plate is 2 * 1 a, the one mounting flange 32 with therein located Has opening 33, also arranged on the frame 11 between the side walls 27 »30, as this for mounting the drum 10 at any desired location on a vehicle or the like is shown. A housing 34 is by any suitable means, for example through slots 35 in element 31 » attached to the support member 31, which receive the forked end of the support member 31, like this can be seen from FIG. 3.

Tieiterhin is a differential lever device for Movement of the locking rods into a position for engaging the toothed disc or ratchet wheel 12 intended. In a preferred embodiment, this differential lever device has a Rocker arm 36 on which, according to FIG. 3, two spaced apart, and essentially upwards and outwardly directed arms 37> 30 that are integral are arranged on a base portion 39. The housing 34 includes a substantially axially extending Opening 40 for receiving a downwardly extending button 4l which is integrally attached to the underside of the base portion 39 is formed. As can be seen from Fig. 3, the button 4l, for example, as on surface 42, tapered on its underside for reasons set forth below are explained in more detail.

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The differential lever device for locking the ratchet wheel 12 also has a weight-loaded Element 47 with an actuating member or adjusting member which is fixedly arranged in an axially extending opening 44 in element 47. That Organ 43 has an enlarged one at its upper end Head portion 45 within the housing 3 ^ is retained by the holding element 31, as shown in Fig. 3 is illustrated. The top surface of the Head section 45 is to form a concave Cavity 46 deepened. As can be seen from Fig. 3, the conical surface 42 of the button element is seated 4l in the cavity 46 and moves on this when the element 47 is displaced, as explained below will. The housing 34 finally contains on its top undercut sections 3 ^ a, so that the locking bars 251 26, which are in engagement with the arms 37 »38 of the rocker arm 36, in a opening 40 a of the housing 34, shown in dashed lines, are movable. A dashed line Pin 4O b can be formed in one piece with lever 36 and be movable into the opening 40 a.

From Figs. 3 and 4 it can be seen that the locking rod 25 has a substantially rectangular cross-section, with the end 48 in the manner shown is rounded, while the other end 49 is substantially is pointed to a point. Similarly, the locking bar 26 can be attached to the end 50 be rounded, with the end 50 lying close to the tapered end 49 of the locking rod 25, while the end 51 »that of the rounded end 50 away, tapers to a point.

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According to Fig. 2, the openings 28, 29 are essentially triangular and have rounded tips to accommodate the respective rounded ends 48, 50 of the locking rods 25 »26. The reduced ends 49 a, 51 a of the locking bars 25, 26 are thus within their associated openings 28, 29 along the sides movable, which lie opposite the tips and are fixed by the walls forming the openings 28, 29. or withheld.

Each locking rod 25 »26 contains two pawls 25'j 26 · arranged at a distance from one another, which are arranged in mutual relation to one another and opposite the ratchet wheel 12 on the drum 10 that, when one pawl tip, ie the tapered ends 49, 51 »Lies radially to the tooth tip of a ratchet wheel, the other pawl tip lies in the middle between two ratchet wheel tooth tips. This is clearly shown in Figure 4, wherein a portion of the ratchet wheel 12 is illustrated. When the tip 51 lies radially to the tooth tip 52 of the ratchet wheel 12 or is aligned radially to the tooth tip 52, the other ratchet tip 49 is generally in the middle between the tooth tips 52 and 53 * Soll the ratchet wheel 12 and thus the shaft 13 are locked or blocked, the pawls 25 ' _t 26 · are forced simultaneously by the two tips or arms 371 38 of the rocker arm 36 into the engaged position. The third point on the lever 36, that is to say the button 41, can be actuated by the movement of the element 47, which is the pendulum or swing weight which detects a braking or deceleration of a vehicle or car.

This means that when the element 47 or a displacement

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Movement due to a strong carriage acceleration of the head portion 45 of the organ 43 the button 4l in the cavity 46 oscillates, -which the rocker arm 36 is moved within the opening 40 a, as can be clearly seen from FIG.

When the button 41 is operated in this way to lock the ratchet wheel 12, tip-to-tip contact can occur in a ratchet as described above. That is, the tips 51 of the locking rods 26 'can engage with the tooth 52 of the wheel 12 - and also with the teeth of the flange 23 - when the ratchet wheel 12 rotates in the direction indicated by the arrow. However, if the peak-peak does not occur -contact or is not observed, the other locking rod 26 is in a position to engage i _n the tooth 52. ^T he pawls tip 49 of the pawls 25 'are thus automatically in a distance between the teeth 52 and 53 of the wheel 12 opposite one another and in this way are conveniently arranged in order to come into contact with the next, following tooth of the wheel 12, ie the tooth 52. In addition, if a pawl tip should slip or bounce out of the contact position, it will automatically produce a special drive or a special movement due to the differential lever device or the rocker arm, so that the other pawl tip comes into engagement or touching contact. In this manner, the lever means urges the second tip into engagement with the teeth of the wheel 12 should the first tip slip or bounce out of contact.

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The above-mentioned differential lever means for creating a third point of movement for the locking rods 25 »26 can be modified. For example, the point of engagement on the wheel 12 by the pawls 25 ^r , 26 'according to Pig. 5 lie on the top of the ratchet wheel instead of on the bottom side, as was described with reference to "FIGS. 1 to 4. In this embodiment, in which the parts corresponding to those in FIGS the head section 58 of the actuating member 43 does not have an upper cavity, such as the cavity 46. The upper surface 59 of the member 43 abuts against the lower surface 60 of a reversing lever 61. There are two pawls 62, 63 with tapered pawl points 64 and 65, respectively fixedly connected to the lever 61. This can be achieved in that a retaining member 46 is fixedly connected to the upper surface 47 of the lever 6l and the pawl 62 is attached thereto 69 of the lever 67 can be attached in the manner shown.

The lever 6l can by a suitable device with openings similar to openings 28, 29 are held, these openings for the pawls 62, 63 are provided, as has been explained with reference to FIGS.

When the lever 6l through the element 47, i.e. through the Contact of head section 58 with surface 60 of the Hebeig 6IL is moved, the lever 6l moves, around the pawls 62, 63 in contact with the teeth that

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Ratchet wheel 12 and to be brought into engagement with the flange 23, not shown. From Fig. 5 it follows that that the pawl tip 65 is in touching contact with the tooth 5 ^ of the ratchet wheel 12, while the Pawl tip 64 is substantially midway between teeth 54 and 55, as above has been described.

In FIG. 6, the parts corresponding to the parts according to FIG. 1 to FIG. 1 are provided with the same reference numerals. The device for locking the ratchet wheel 12 may include a toggle lever 71 which is attached to each his arms 74, 75 pawls 72, 73 carries. The handles 72, 73 are designed in the manner already described and each have a tapering Tip 76, 77 on. For fastening the pawls 72, 73, which can be parts of suitable locking bars, As already described above, any suitable device on the toggle lever or angle lever 71 are attached, for example by arrangement of a slot 78 ση an arm 74, the Slot 78 receives a pin 79. A holding element 8O is fixedly arranged on the pin, while the Pawl 72 by a suitable device with the Pin 79 is connected. The other pawl 73 is fixedly attached to a pin 82 that of the other Arm 75 is worn. The tip-to-tip contact of the ratchet tips 76, 77 with the teeth of the ratchet wheel 12 is clearly evident from FIG. 6. The tip 77 is thus radially aligned with the tooth 56, while the tip 76 lies substantially midway between the teeth 56 and 57.

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Any suitable means can be used to move the lever 71. For example, a slot 83 can be provided in the main body portion 84 of the lever 71. A plate 85 may be movable within slot 83 and engageable with sides defining slot 83. The plate 85 can respond to the belt webbing, that is to say react to a rapid unwinding of the belt webbing lk from the shaft 13, as is generally known in seat belts or seat belts. Thus, when the plate 85 is moved, the planer 71 is also moved so as to bring the pawl tips 76, 77 of the pawls 72, 73 into engagement with the teeth of the ratchet wheel 12 - and the chuck 23 - as previously described became. The various elements described above in relation to FIG. 6 can be arranged in the frame 11 in any suitable manner within openings similar to the openings 28,29, these openings being provided for receiving the locking bars of the pawls 72,73.

7 and 8, a further modified device for blocking the ratchet wheel 12 is shown. A cap 86 is attached to the side of the frame 11 opposite the spring socket connection 21. The parts corresponding to the elements according to FIGS. 1 to k are again provided with the same reference numerals. A split ring coupling 87 extends around the perimeter of the cap 86 as shown in FIGS. The coupling 87 includes an inwardly extending projection 88 (Fig. 7) 1 which is provided for the purpose described below; one

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turnstile-like disc coupling 90 is within of the frame 1 held between the cap 86 and the inner part of the drum. A mounting plate 91 can be used to attach the cap 86 and the couplings 87 »90 to the frame Π be used.

Two locking bars 92, 93 ', which are similar to the locking bars described, have pawls with tips 9k, 95 which are arranged on the frame 11 below the ratchet wheel 12. A pawl spring is connected to each locking bar 92,93. In this way, one end of the spring 96 is secured within a cutout area 97 of the frame 11; the spring then runs around a two-part lever arm 98 (Fig. 8) and carries the locking rod 93.In the same way, a second pawl spring is fastened at one end within an opening 100 in the frame 11 and then runs around a two-part, second lever arm 101, which carries the locking bar 92.

The projection 88 extends into an opening 102 of the lever arm 100. The arm 89 of the coupling 90 faces a lug 103 (FIG. 7) which extends into an opening in the arm 98.

As can be seen, conventional inertial devices can be connected to the cap 86 to determine a sudden withdrawal of the webbing lk and thus the rotation of the cap 86. The force of the rotation of the cap 86 is then transmitted through couplings 87, 90 to locking rods 92, 93, which against

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- i8 -

the spring force of springs 96, 99 rotated! rerdon and get into engagement with the teeth of a ratchet wheel 12. The pawl tips 9 '' * '95 are arranged in such a way that when the one pawl tip hits a tooth tip of the ratchet wheel 12, causing it to engage with the respective *. Tooth of the ratchet wheel is prevented, the other ratchet tip is able to mesh with one of the other teeth. This means that the ratchet tip 95 as shown in FIG. 8 just comes into engagement with the tooth 56, while the ratchet tip 9 ^ is located approximately in the middle between the teeth 53 and 5 ^. When the locking rods 92, 93 are moved into the position shown in dashed lines, as previously described, the tips 9k, 95 will come into engagement with the teeth of the ratchet wheel 12, as has already been done with reference to FIGS is described. The above explanations with regard to the engagement in the ratchet wheel 12 can also be applied to the engagement in the guide flange 23.

The invention provides a parked to an emergency braking system is thus provided for use in seat belts or safety belts or the like. Dynamic failure commonly found in such systems is minimized due to the use of a differential device, which differential device moves two pawls into locking engagement with the ratchet wheel of the system. The usage

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by ZT. ^The pawls that are operated by such a device thus creates a much more reliable seat belt or seat belt system.

The invention thus creates a drum for receiving a belt or seat belt on a rotatable bearing shaft. The drum contains spring devices for retracting the belt and a toothed ratchet wheel, which is connected to the shaft for rotation. Actuated when the belt is quickly unwound from the shaft a device responsive to inertia forces two locking rods for engagement in the ratchet wheel and to stop its rotation. Each spur rod has a ratchet tip and if one of the ratchet tips is radial to one of the tooth tips of the ratchet wheel is aligned, the other pawl tip is midway between two adjacent ones Teeth of the ratchet wheel. When the locking bars are moved into engagement with the ratchet wheel, ensure the two pawl tips and their direction in relation to the teeth of the ratchet wheel, that at least one pawl tip is in a suitable position to engage with the To get ratchet wheel in case the other ratchet tip should disengage or not in Comes into contact with the ratchet wheel. A differential lever device can be used to move the pawl tips may be provided for engagement with the ratchet wheel. The latter facility thus brings a Pawl tip in engagement with the ratchet wheel in the event a first pawl tip is out of engagement slides out or does not engage in any other way.

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Claims (10)

- 2Q - mo 4678 claims 1) drum for receiving a belt strap or the like, characterized in that a frame (11) with a shaft (13) mounted therein for rotational movement, one end of the belt strap ( lk ) with the shaft (13) for winding on the shaft ( 13) is connected, a spring device (21) connected to the shaft (13) and the frame (11) for rotating the shaft (13) in one direction for the purpose of retracting or retracting the belt strap ( Ik ) around the shaft, a with the shaft (13) rotatable and attached to the circumference thereof ratchet gear with a plurality of spaced apart teeth which extend in a direction opposite to the direction of rotation of the shaft (13) due to the spring device (21), and. a device (25, 26; 92, 93) for locking a rotation of the shaft (13) in a direction opposite to the direction of rotation of the shaft due to the spring device (21) is provided, that the locking device has two locking rods attached to the frame (11) which each have a ratchet tip (25, 26) and are movable within the frame (11) from a first position disengaged from the ratchet wheel to a second position in engagement with the ratchet wheel, so that the ratchet tips are in the second position have such a distance from one another that with a radial alignment of the pawl tip of one locking rod to a tooth of the toothed ratchet wheel, the other pawl tip of the second locking rod is aligned with the center between two adjacent teeth of the toothed ratchet wheel. 409845/0311 2) drum according to claim 1, characterized in that the locking device arranged in the frame or housing (11) has a differential lever device which is operatively connected to the locking rods for their movement between the first and second positions, that the differential Lever device has a first and second, the locking rods contacting section and a third section, and that a device (36, 45, krj ) with the frame (11) for operational contact of the third section for actuation of the lever device, which in turn has a locking rod between moved to a first and second position independently of the other locking rod. 3) drum according to claim 2, characterized in that connected to the frame or frame (11) Facility responds to mass forces. 4) drum according to claim 3 »dadtirch characterized in that the differential lever device has a rocker arm (36) with a base element and two essentially upwardly extending arms (36, 37) which are at a distance from one another, one of which is against the Bottom surface of one of the locking rods and the other arm abuts against the bottom surface of the other locking rod that the third section contains a downwardly extending button ( kl ), which is rounded at its lowest end, that the inertia forces on 409845/031 1 appealing or inertia-sensitive device a weight-loaded element (47) with an integrated has upper head portion with a cavity on the upper surface and that the rounded Section of the button (4l) rests in the cavity (42) and is displaceable on this when the weight-loaded element between the he ^ eXeim ^ i « device actuating positions is moved. 5) drum according to claim 4, characterized in that the locking rods in the longitudinal direction to Frame (11) and extend substantially parallel to the axis of the shaft (13) that the frame (11) two screen walls (27 »30) and at least two spaced apart openings in each side wall that the opposite ends of the locking bars extend through them Openings extend and that each opening a guide device for the associated locking rods when moving between the first and second positions. · 6) drum according to claim 3 »characterized in that that the differential lever device is an original control lever (6l) has, on which each locking rod is fixedly arranged, that the third position of the Underside of the lever is formed that the inertia sensitive Means a weighted member (47) having an integral upper head portion contains and that the upper surface of the head portion against the underside of the lever to Movement of the same with a movement of the weight-bearing yden loaded element between / actuating the lifting device Positions. 409845/03 1 1 7) drum according to claim 3 »characterized in that that the differential lever device a Kniebzw. Angle lever (71) with at a distance from each other has located arms, on each of which a locking rod is fixedly arranged. 8) drum according to claim 1, characterized in that the device fixed in the frame a cap (86) rotatably attached to the frame and one operable to the cap (86) as well , rotatable with this coupling device connected (87 »90) shows that the coupling device approaches the operational contact with two Ratchet control arms includes that a locking bar is attached to each arm and that a spring device to "bias the locking rods in a disengaged from the teeth of the ratchet wheel position is associated with each arm. 9) Drum according to one or more of the preceding Claims, characterized in that with a substantially radial alignment of the pawl tip one locking rod to a tooth of the ratchet wheel, the pawl tip of the other locking rod is arranged in the space of the ratchet wheel, which is formed by two adjacent teeth of the ratchet wheel is formed. 10) A drum as claimed in one or more of the preceding claims, characterized in that the arranged in the frame (11), the differential lever means comprising means responsive f _au rapid pulling of the webbing (l4). 409845/0311 Blank